Salmonella Alachua: causative agent of a foodborne disease outbreak

ww w . e l s e v i e r . c o m / l o c a t e / b j i d

The

Brazilian

Journal

of

INFECTIOUS

DISEASES

Original

article

Salmonella

Alachua:

causative

agent

of

a

foodborne

disease

outbreak

Ivete

Aparecida

Zago

Castanheira

de

Almeida

_,

_Jacqueline

_Tanury

_Macruz

_Peresi

_,

Elisabete

Cardiga

Alves

_,

_Denise

_Fusco

_Marques

_,

_Inara

_Siqueira

_de

_Carvalho

_Teixeira

_,

Sonia

Izaura

de

Lima

e

Silva

_,

_Sandra

_Regina

_Ferrari

_Pigon

_,

_Monique

_Ribeiro

_Tiba

_,

Sueli

Aparecida

Fernandes

a_{InstitutoAdolfoLutz,CentrodeLaboratórioRegionaldeSãoJosédoRioPreto,SãoPaulo,SP,Brazil}

b_{VigilânciaEpidemiológicaMunicipaldeCatanduva,SãoPaulo,SP,Brazil}

c_{InstitutoAdolfoLutzCentral,SãoPaulo,SP,Brazil}

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received3October2014 Accepted19December2014 Availableonline4February2015

Keywords: Foodbornediseases SalmonellaAlachua Drugresistance Brazil

a

b

s

t

r

a

c

t

Objectives: Theaimofthisstudyistoreporttheoccurrenceofthefirstoutbreakoffood

poisoningcausedbySalmonellaAlachuainBrazil,aswellastheantimicrobialsusceptibility andthegeneticrelatednessofSalmonellaAlachuastrainsisolatedfromclinicalandfood samples.

Materialandmethods: Toelucidatetheoutbreak,anepidemiologicalinvestigationwas

car-riedout,andtwosamplesofcommonfoodweretested–mayonnaisesaladandgalinhada

(atraditionalBraziliandishofchickenandrice)–accordingtotheCompendiumof meth-odsforthemicrobiologicalexaminationoffoods.Fivestoolsamplesweretestedemploying classicmethodsfortheisolationandidentificationofenterobacteria.StrainsofSalmonella werecharacterizedforantibioticsusceptibilityaccordingtotheClinicalandLaboratory Stan-dardsInstituteguidelines(2013),andsubmittedtopulsed-fieldgelelectrophoresisanalysis, performedaccordingtotheCentersforDiseaseControlandPreventionPulseNetprotocol.

Results:A totalof94peoplewereinterviewedafteringestingthefood,66 ofwhomhad

becomeill.A60-yearoldfemalepatientwhowashospitalizedinaseriouscondition, devel-opedsepticshockanddiedtwodaysafterconsumingthefood.ThepresenceofSalmonella

Alachuawasconfirmedinalltheanalyzedstoolsamples,andinthetwotypesoffood. Thefivestrainsshowedhigherthanminimuminhibitoryconcentrationvaluesofnalidixic acid(≥256␮g/mL)andreducedciprofloxacinsusceptibility(minimuminhibitory concentra-tion=0.5␮g/mL).Thepulsed-fieldgelelectrophoresisanalysisrevealedindistinguishable patternsinSalmonellaAlachuastrainsisolatedfromclinicalandfoodsamples.

∗ _{Correspondingauthorat:RuaAlbertoSufredineBertoni,n}◦_{2325,SãoJosédoRioPreto,SP15060-020,Brazil.}

E-mailaddresses:iazcalmeida@ial.sp.gov.br,izacal@ig.com.br(I.A.Z.C.Almeida).

http://dx.doi.org/10.1016/j.bjid.2014.12.006

Conclusion: Thedatapresentedhereinconfirmthefoodbornediseaseoutbreak.Theyalso allowedfortheidentificationofthesourceofinfection,andsuggestthatproductsfrom poultryarepotentialreservoirsforthisserotype,reinforcingtheimportanceofwarning consumersaboutthedangerofpossiblecontamination.

©2015ElsevierEditoraLtda.Allrightsreserved.

Introduction

Salmonella,agenusofzoonoticenterobacteriaresponsiblefor

outbreaksofinfectionsinbothhumansandanimals,has sig-nificanteconomicimportanceworldwide.1–3 _{Itisestimated}

that Salmonella causes 93.8 million human infections and

155,000deathsperyeararoundtheworld.3_{From2000to2013,}

Salmonellawasthe infectiousagent mostcommonlylinked

tooutbreaksoffoodpoisoninginBrazil,withatotalof1560 episodesrepresenting38.3%ofallagentsidentifiedduringthe saidperiod.4

Bothchildrenandtheelderly,aswellas immunocompro-misedindividualswithsalmonellosismayseethecondition evolve tomore severe stages as, upon entering the blood-stream, the bacteria can cause extraintestinal infections.5

Theriskofinvasivediseaseistwotosixtimeshigherthan with other foodborne pathogens6_{; the death rate is also}

higher.7

Salmonella Alachua was first described in 1952, during

a study of the effects of salmonellosis in pigs in the city of Alachua, Florida, where it was isolated in a soil sam-ple from a pigfarm.8 _{However,the first reported isolation}

in animals was in 1955 after several outbreaks of enteri-tis inchickens fromdifferent farms inBombay,India, that resulted in a considerable loss of birds.9 _{Since then,}

iso-lation has proved uncommon worldwide,as it is found in humanand non-human samplesata rate offrom 0.03 to 3.8%.10–14

Inthisstudy,wereporttheoccurrenceofthefirstoutbreak offoodpoisoningcausedbySalmonellaAlachuainBrazil,in acityinthenorthwesternregionoftheStateofSãoPaulo. Moreoverwereportoftheantimicrobialsusceptibilityandthe geneticrelatednessofSalmonellaAlachuastrainsisolatedfrom clinicalandfoodsamples.

Materials

and

methods

Epidemiologicalinvestigation

Inordertobetterexplaintheoccurrenceofafoodborne dis-ease outbreak in a city in the northwestern region of the State of São Paulo in November 2012, an epidemiological investigation was carried out by the local health surveil-lance team, withthe collectionofsamples oftheingested food–mayonnaise saladandgalinhada (atraditional Brazil-iandish ofchicken andrice)–and stoolsamplesfrom five patients.AllthetestswereperformedattheRegional Labo-ratoryCenterofInstitutoAdolfoLutzinSãoJosédoRioPreto (RLCIAL).

Microbiologicalanalysisofthefood

Thefoodwasanalyzedaccordingtothemethodsdescribedin theCompendiumofMethodsfortheMicrobiological Examina-tionofFoods–APHA15_{forcontaminationbycoliformgroup}

bacteria,Staphylococcusaureus,Bacilluscereus,Clostridium

per-fringensandSalmonella.

The procedures for isolation and identification of

Salmonella, were carried out through pre-enrichment of

25gsamplesbyhomogenizationwith 225mLlactosebroth (10−1dilution),andincubationovernightat36±1◦C.Selective enrichmentwas performed intetrathionate(TT) broth and modifiedRappaport-Vassiliadis(RV)broth,followedby incu-bationat36±1◦Cfor24hand42◦Cfor24–48h,respectively. Each enrichmentbroth was streaked onto selectiveplates:

Salmonella-Shigella agar (SS), brilliant green agar (BG) and

xyloselysinedeoxycholateagar(XLD),andincubatedfor24h at36±1◦C.15

Eventhoughnootherbiochemicaltestswereperformed, characteristiccoloniesofeachplatewerebiochemicallytested usingonlyIALmedium16_{forthepresumptiveidentificationof}

Enterobacteriaceaeandincubatedfor24hat36±1◦C.Strains

withpresumptiveidentificationofSalmonellaweresubmitted toserologicaltestsusingpolyvalentsomatic(O)andflagellar (H)antiseraproducedbytheLaboratoryofEntericPathogens oftheInstitutoAdolfoLutz.

ThestandardmethodologyforthestudyofSalmonella15

rec-ommends the use ofthe presence/absence method in25g ofa foodsample. Thehighestdilution inwhichSalmonella

is demonstrably present in the food sample was used as a complement to the testing, with the purpose of deter-mining which food had the highest microbial load. Albeit important, this is not a quantitativemethod. For this, we started with10mLofa10−1dilution,serialdilutionsofthe food samples were performed in tubes containing lactose broth up to a dilution of 10−9. After incubatingthe tubes for18–24hat36±1◦C,thepresenceofturbiditywasverified inthedifferentdilutions.Theinoculumfromalltubesthat presentedturbiditywas submittedtoselectiveenrichment, isolationandidentificationprocedures,pursuanttotheAPHA methodology.15

Stoolanalysis

Stoolsampleswerecollectedfromatotaloffivepatientsby swab and transported in Cary-Blair mediumto investigate

Escherichia coli, Aeromonas spp., Shigella spp. and Salmonella

spp.AtRLCIAL,theswabswereseededinplateswith Mac-ConkeyAgar(MC), Salmonella-ShigellaAgar(SS)andSorbitol MacConkeyAgar(MCS),and incubated for24hat36±1◦C.

Subsequently,theswabwasplacedinatubecontaining10mL ofTetrathionate(TT)brothandincubatedfor24hat36±1◦C forselectiveenrichment.Afterthisperiod,theTTbrothwas inoculatedonplateswithMCandBrilliantGreenAgar.After incubationfor18–24hat36±1◦C,alltheplateswiththe selec-tivemediumwereexaminedforcolonymorphologyandfor utilization of lactose/sorbitol, which are used to inoculate theIAL medium16 _{forthepresumptiveidentification ofthe}

researchedmicroorganisms.

StrainswithpresumptiveidentificationofSalmonellawere submittedtoserologicaltestsusingpolyvalentsomatic(O)and flagellar(H) antiseraproducedbythe LaboratoryofEnteric Pathogens,InstitutoAdolfoLutz.

Serotyping

AlltheisolatesofSalmonellafromthefoodandstoolsamples weresenttotheCentralLaboratoryoftheInstitutoAdolfoLutz (CLIAL)forcompleteserotypingonthebasisofsomaticOand phase1andphase2oftheHflagellarantigensby agglutina-tiontestswithantiserapreparedintheLaboratoryofEnteric Pathogens,InstituteAdolfoLutz,SãoPauloasspecifiedinthe Kauffmann–WhiteprotocolforSalmonellaserotyping.17

Susceptibilitytesting

Antimicrobial susceptibility testing was performed for all isolates using the disk diffusion method according to the guidelines of the Clinical and Laboratory Standards Insti-tute – CLSI.18 _{The following antimicrobial disks (Oxoid)}

wereused:nalidixicacid(30␮g),amoxicillin–clavulanicacid (20/10␮g), amikacin (30␮g), ampicillin (10␮g), aztreonam (30␮g), ceftazidime (30␮g), cefotaxime (30␮g), ceftriaxone (30␮g),cefepime(30␮g),ciprofloxacin (5␮g), chlorampheni-col(30␮g),streptomycin(10␮g),gentamicin(10␮g),imipenem (10␮g), trimethoprim–sulfamethoxazole (1.25/23.75␮g), sul-fonamide(250␮g),andtetracycline(30␮g).Categorizationof thediameterofhalosinsusceptible,intermediateorresistant followedCLSIrecommendations.18

Minimum inhibitory concentrations (MIC) were deter-minedfornalidixicacidandciprofloxacinbyEtest(ABBiodisk, Solna,Sweden)accordingtothemanufacturer’s recommen-dations.TherangeofMICofciprofloxacinforSalmonellawas recentlychanged tosusceptible: ≤0.06␮g/mL; intermediate susceptible:0.12–0.5␮g/mL;resistant:≥1␮g/mL.18

E.coliATCC25922andE.coliATCC35218wereusedas ref-erencestrainsforantimicrobialsusceptibilitytesting.

Pulsedfieldgelelectrophoresis

Pulsed field gel electrophoresis (PFGE) analysis was per-formedforalltheisolatesatCLIALaccordingtotheCenters for Disease Control and Prevention (CDC) PulseNet pro-tocol(www.cdc.gov/pulsenet/pathogens/index.html). Briefly, celllysis wasfollowedbyproteinaseK treatmentandDNA restriction with XbaI (New England Biolabs, Ipswich, MA). Electrophoresis was performed with a CHEF DRIII system (BioRad Laboratories Inc., Hercules, CA) using the follow-ing run parameters: a switch time of 2.2–63.8s and a run

time of 20h. Salmonella Braenderup H9812 was used as a

molecularsizemarker.19_{TIFFimageswereanalyzedusingthe}

BioNumerics5.0software(AppliedMaths).Dice’scoefficient withtoleranceof1.5wasusedtocalculatesimilarity using theUnweightedPairGroupMethodwitharithmeticaverages (UPGMA).

Results

Epidemiologicalinvestigation

Of the 94 people interviewed after the foodborne out-break, the epidemiological investigation found that the consumption ofmayonnaisesalad and galinhadawas com-mon to the entire group; 66, both children and adults, had become ill. The median incubation period was 72h, and the main symptoms observed were: diarrhea 63/66 (95.4%),abdominalpain50/66(75.7%),nausea40/66(60.6%), fever 27/66 (40.9%), vomiting 23/66 (34.8), and headache 22/66 (33.3%). Attack rates by age group are shown in

Table1.

Accordingtotheinvestigation,a60-yearoldfemalepatient whowashospitalizedinaseriouscondition,developedseptic shockanddiedtwodaysafterconsumingthefood.

Microbiologicalanalysis

ThepresenceofSalmonellawasconfirmedinalltheanalyzed stoolsamplesandinbothtypesoffood,consequentlyitwas isolatedindilutionsof10−7and10−2ofthesaladmayonnaise

andgalinhada,respectively.Nootherpathogenswereisolated

fromthefoodorstoolsamples.

TheMostProbableNumbers(MPN)ofthermotolerant col-iformsfoundinthemayonnaisesaladandgalinhadasamples were>2400/gand240/g,respectively.

Serotyping

All thestrainsisolatedfromhumanandfoodsourceswere identifiedasSalmonellaentericaserovarAlachuaby agglutina-tiontests.

Antimicrobialsusceptibility

All the Salmonella Alachuastrains demonstrated resistance

tonalidixicacid andreducedsusceptibility tociprofloxacin (intermediateresistant).However,allofthemweresusceptible totheotherantimicrobialstested.

ThesevenstrainsshowedhigherMICvaluesfornalidixic acid (≥256␮g/mL) and reduced ciprofloxacin susceptibility (MIC=0.5␮g/mL).

Pulsedfieldgelelectrophoresis

A dendrogram, generated by PFGE patterns of Salmonella

Alachua strains using XbaI as the restriction enzyme, is showninFig.1.OnePFGEpatternwasidentifiedamongthe

SalmonellaAlachua clinicaland food isolatesanalyzed.The

Table1–AttackratebyagegroupofthesubjectsexposedtoriskbytheingestionoffoodcontaminatedbySalmonella.

Agerange(years) Subjectsexposedtorisk Total,n Attackrate(%)

Individualssick,n Individualsnotsick,n

<1 – – – – 1–9 7 1 8 87.5 10–20 6 2 8 75.0 20–39 28 11 39 71.8 40–49 10 4 14 71.4 50–59 5 7 12 41.7 ≥60 10 3 13 76.9 Total 66 28 94 70.2

Discussion

Currently,Salmonellaisoneofthemostcommon microorgan-ismsinvolvedinfoodbornediseaseoutbreaksworldwide.4,20,21

IntheUnitedStates,SalmonellaAlachuacorrespondsto0.05% oftheisolatesidentifiedintheperiodfrom1999to2009,while

SalmonellaTyphimuriumandSalmonellaEnteritidiswerethe

prevalentserotypes,accountingfor18.5%and16.3%ofcases, respectively.13

Asimilar situation occurred inMexico, where, between 1972and1999,only26(0.1%)strainsof24,394Salmonella iso-latesfromvariouspublichealthandprivatelaboratorieswere foundtobeSalmonellaAlachua.12

Three(0.03%)andone(0.04%)isolatesofSalmonellaAlachua identifiedinnon-humanand humanmaterial,respectively, wereregisteredintheStateofSãoPaulo,Brazil,indifferent periods.11,22_{Moreover,intheStateofGoiás,Brazil,Salmonella}

Alachuawasisolatedintwo(3.8%)samplesfrombirdtransport boxliners.14

According toAlmeida et al.23 _{no presenceof Salmonella}

Alachuawasobservedinhumanandnon-human(food) mat-terduringthe1990sinthesameregionasthecurrentreported outbreak.Theonlytimeinwhichthisserotypewasisolated

wasin2007,fromasampleofraweggs,duringaninvestigation ofafoodbornediseaseoutbreak.However,itwasnot consid-eredthecausativeagent,astheSalmonellaentericaserotype Infantiswasisolatedinallthestoolsamplesoftheaffected individuals(12patients).24

AsignificantincreaseinthenumberofSalmonellaAlachua isolates(27to88)observedintheUSAin1982,corresponding toanupsurgeof226%overthepreviousyear,wasattributed totheadoptionofchildrenfromanurseryinCalcutta,India, byAmericanfamilies.25_{Giventheabove,oneshouldconsider}

thepossibilitythatthisserotypemayhavehadarelevant epi-demiologicalexpressionforsometimeinIndia.

Changesintheprevalenceofserotypeshavebeenobserved inseveralstudies,22,26–28_{henceanyserotype,howeverunusual}

oruncommon,maybecomeemergentandcauseserious infec-tionsoroutbreaks.

Some serotypes are frequently associated with certain classesoffood.Thus,studiesontheserotypes characteriza-tionprovideinformationonreservoirs,routesoftransmission and prevalencein aspecific region,particularly when out-breaksoffoodbornediseasesoccur.4,29,30

Notwithstanding the fact that there are few reports on

SalmonellaAlachua,productsoriginatingfrompoultryfarms

canbeconsideredpossiblereservoirsforthisserotype.14,24

49.3 100 Human Human Human Human Human Food Food Marker 10-30571 10-30555 10-30572 10-30560 10-30557 10-30553 10-30552 Source Type LabID 60 80 100 2000 1500 1200 1000 700.00 600.00 500.00 100.00 350.00 300.00 250.00 200.00 150.00 80.00 60.00 10.00 30.00 20.00 PFGE-Xbal PFGE-Xbal

Dice (Opt 1.50%) (Tol 1.5%-1.5%) (H>0.0% S>0.0%) [0.0%-100.0%]

Fig.1–DendrogrampulsedfieldgelelectrophoresispatternsofSalmonellaAlachuastrains.LabID(identificationnumber) andsourcetype(humanorfood)oftheSalmonellaAlachuastrainsanalyzed.Marker:SalmonellaBraenderupH9812digested withXbaIenzymewasusedasamolecularsize.

ConsideringthefactthatSalmonellaAlachuahasbeen iden-tifiedwiththesamegeneticconnectioninboththeisolated foods,itcanbesuggestedthatcross-contaminationoccurred betweenthetwotypesoffoodanalyzed.Cross-contamination canoccur asaresultofinadequate manipulation,and use ofcontaminatedkitchenutensils,andmaybecomecritical, dependingontheamountoftimethattheproductisexposed toimproperstoragetemperatures.31_{Itshouldbeemphasized}

thattheuseofraweggsinthepreparationofthemayonnaise saladduringtheepidemiologicalinvestigationoftheoutbreak wasnotconfirmed.Therefore,thechickenmeatusedforthe preparationofgalinhadacanbeconsideredthelikelysourceof

SalmonellaAlachua.

TheinfectiousdoseofSalmonellavariesbetween105_and

108_{cells,withinfectivedosesaslowas≤10}3_{beingreported}

in immunocompromised patients, while certain serotypes arerelatedtofoodbornediseaseoutbreaks.5,32_{Consequently,}

despitethenon-quantificationofSalmonella,thelargenumber ofaffectedindividualsinthisstudycanbeexplainedbythe presenceofthispathogenatdilutionsof10−7inthesampleof mayonnaisesalad.

Certain reports have demonstrated antimicrobial resis-tance to SalmonellaAlachua strains from both humanand non-humansources.14,33,34 _{Inthisstudy,eventhough there}

wassusceptibilityofSalmonellaAlachuastrainstomostofthe antimicrobialstests,allpresentedresistancetonalidixicacid (MIC≥256␮g/mL)withreducedsusceptibilitytociprofloxacin (MIC=0.5␮g/mL).Theresistancetonalidixicacidcanpredict aresistancetofluoroquinolones,asobservedinthestudy.

Fluoroquinolonesarecurrentlyusedtotreatinvasiveand systematicsalmonellosis,occurringinhumans.Thesearealso effectiveintreatingarangeofdifferentinfections encoun-teredinanimals.Resistancetofluoroquinolonesisrelatively uncommonwithSalmonella.However,inrecentyears,studies havereportedanincreaseinthenumberofclinicalisolates withreducedsusceptibilitytociprofloxacinassociatedwith treatmentfailure.35–37_{Theemergenceofreduced}

susceptibil-itytofluoroquinolonesamongfoodanimalsandhumansis consideredasignificantpublichealthconcern,andshouldbe carefullymonitored.

PFGE revealed indistinguishable patterns in Salmonella

Alachuastrainsisolatedfromclinicalandfoodsamples,thus confirmingthefoodbornediseaseoutbreak;thisalsoallowed for the identification ofthe source ofinfection. PFGE is a standardtypingmethodusedinSalmonellaoutbreak investiga-tionstodeterminetherelationshipanddistributionofgenetic subtypesofSalmonellacirculatingincountries,aswellasthe applicationfortheinvestigationoffoodborneoutbreaks,and todetectemergingpathogens.38

Conclusion

Thisstudy reports on thefirst foodborne disease outbreak causedbytheSalmonellaAlachuaserotypeinBrazil.Thesource ofinfectionwasconfirmedbyPFGE,andallSalmonellaAlachua strainspresentedresistancetonalidixicacid,andreduced sus-ceptibilitytociprofloxacin.

The findings of this study highlight the importance of the numerous and complex activities of Public Health

Laboratoriesinthedevelopmentofnecessaryknowledgeto optimizepreventionandfoodcontaminationcontrol.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

r

e

f

e

r

e

n

c

e

s

1.SockettPN.Theeconomicimplicationsofhumansalmonella infection.JApplBacteriol.1991;71:289–95.

2.MeadPS,SlutskerL,DietzV,etal.Foodrelatedillnessand deathintheUnitedStates.EmergInfectDis.1999;5:607–25.

3.MajowiczSE,MustoJ,ScallanE,etal.Theglobalburdenof nontyphoidalSalmonellagastroenteritis.ClinInfectDis. 2010;50:882–9.

4.Brasil.MinistériodaSaúdeSecretariadeVigilânciaemSaúde –DepartamentodeVigilânciaEpidemiológica.Coordenac¸ão GeraldeDoenc¸asTransmissíveis.VigilânciaEpidemiológica dasDoenc¸asTransmitidasporAlimentos–VE-DTA.Available at:http://www.anrbrasil.org.br/new/pdfs/2014/3PAINEL1 ApresentacaoRejaneAlvesVigilanciaEpidemiologica-VE-DTA-Agosto2014PDF.pdf[accessed31.08.14].

5.D’AoustJY,MaurerJ.Salmonellaspecies.In:DoyleMP,Beuchat LR,editors.Foodmicrobiology:fundamentalsandfrontiers. 3rded.Washington:ASMPress;2007.p.187–236.

6.HelmsM,SimonsenJ,MolbakK.Foodbornebacterial infectionandhospitalization:aregistry-basedstudy.Clin InfectDis.2006;42:498–506.

7.HughesC,GillespieLA,O’BrienSJ.Foodbornetransmissionof infectiousintestinaldiseaseinEnglandandWales,

1992–2003.FoodControl.2007;18:766–72.

8.LoweryWD,SmithWV,GaltonMM,EdwardsPR.Salmonella alachua,anewserotype.JBacteriol.1953;66:118.

9.DasMS,JayaramanMS.Isolationofararespeciesof Salmonella(Salmonellaalachua)fromacuteoutbreaks amongstpoultryinIndia.PoultSci.1955;34:1048–9.

10.BasuS,DewanML,SuriJC.PrevalenceofSalmonellaserotypes inIndia:a16-yearstudy.BullWorldHealthOrgan.

1975;52:331–6.

11.CalzadaCT,NemeSN,IrinoK,etal.SorotiposdeSalmonella identificadosnoperíodo1977–1982,noInstitutoAdolfoLutz, SãoPaulo,Brasil.RevInstAdolfoLutz.1984;44:1–18.

12.Gutiérrez-CogcoL,Montiel-VázquezE,Aguilera-PérezP, González-AndradeMC.SerotiposdeSalmonellaidentificados enlosserviciosdesaluddeMéxico.SaludPublicaMex. 2000;42:490–5.

13.CentersofDiseaseControlandPrevention–CDC.National

Salmonellasurveillanceannualsummary2009.

Laboratory-confirmedSalmonellaisolatesfromhuman sourcesreportedtoCDCbyserotypeandyear,1999–2009. Availableat:http://www.cdc.gov/ncezid/dfwed/PDFs/ SalmonellaAnnualSummaryTables2009.pdf[accessed 22.01.14].

14.MoraesDMC[Dissertac¸ãodemestrado]Fontedeinfecc¸ãoe doperfilderesistênciaaantimicrobianosdeSalmonellasp. isoladasdegranjasdefrangodecorte.Goiânia:Escolade VeterináriadaUniversidadeFederaldeGoiás;2010.

15.DownesFP,ItoK.Compendiumofmethodsforthe microbiologicalexaminationoffoods.4thed.Washington, DC:AmericanPublicHealthAssociation;2001.

16.PessoaGVA,SilvaEAM.Milieupourl’identification présomptiverapidedesenterobactéries,desAeromonaset desVibrions.AnnMicrobiol.1974;125A:341–7.

17.PopoffMY,MinorL.AntigenicformulasoftheSalmonella sorovars.8thed.Paris:WHOCollaboratingCentrefor ReferenceandResearchonSalmonella,PasteurInstitute;2001.

18.CLSI–ClinicalandLaboratoryStandardsInstitute. Performancestandardsforantimicrobialsusceptibility testing.In:Twenty-thirdinformationalsupplement.M100-23. Wayne,PA:CLSI;2013.

19.HunterSB,VauterinP,Lambert-FairMA,etal.Establishment ofauniversalsizestandardstrainforusewiththePulseNet standardizedpulsed-fieldgelelectrophoresisprotocols: convertingthenationaldatabasestothenewsizestandard.J ClinMicrobiol.2005;43:1045–50.

20.EFSAJournal.TheEuropeanUnionsummaryreportontrends andsourcesofzoonoses.Zoonoticagentsandfood-borne outbreaksin2010,vol.10;2012.p.2597.

21.CentersforDiseaseControlandPrevention–CDC.Estimates offoodborneillnessintheUnitedStates;2013.Availableat:

http://www.cdc.gov/foodborneburden[accessed25.11.13]. 22.TavechioAT,FernandesAS,NevesBC,DiasAMG,IrinoK.

ChangingpatternsofSalmonellaserovars:increaseof SalmonellaEnteritidisinSãoPaulo,Brazil.RevInstMedtrop SãoPaulo.1996;38:315–22.

23.AlmeidaIAZC,PeresiJTM,CarvalhoIS,etal.Salmonella: sorotiposidentificadosnaregiãodeSãoJosédoRioPreto/SP, noperíodode1990–1999.RevInstAdolfoLutz.2000;59:33–7.

24.AlmeidaIAZC,PeresiJTM,MarquesDF,etal.Salmonella: SurtosdeorigemalimentarocorridosnaregiãodeSãoJosédo RioPreto-SP,noperíododejaneirode2006aabrilde2007.In: Anais:VIIEncontrodoInstitutoAdolfoLutz,SãoPaulo,Brasil. 2007.

25.CentersforDiseaseControlandPrevention–CDC.Current trendshumanSalmonellaisolates–UnitedStates,1982.Morb MortalWklyRep.1983;32:598–600.Availableat:http://www. cdc.gov/mmwr/preview/mmwrhtml/00000176.htm[accessed 25.03.13].

26.TaunayAE,FernandesAS,TavechioAT,NevesBC,DiasAMG, IrinoK.TheroleofPublicHealthLaboratoryintheproblemof salmonellosisinSãoPaulo,Brazil.RevInstMedtropSão Paulo.1996;38:119–27.

27.CentersforDiseaseControlandPrevention–CDC.Outbreaks ofSalmonellaserotypeEnteritidisinfectionassociatedwith

eatingraworundercookedshelleggs-UnitedStates, 1996–1998.MorbMortalWklyRep.2000;49:73–9.

28.CoganTA,HumphreyTJ.TheriseandfallofSalmonella EnteritidisintheUK.JApplMicrobiol.2003;94:1145–95.

29.PeresiJTM,AlmeidaIAZC,LimaSI,FernandesSA,Tavechio AT,GelliDS.Salmonella:determinac¸äodesorotipose resistênciaaagentesantimicrobianosdecepasisoladasde carcac¸asdefrangocomercializadasnaregiäodeSãoJosédo RioPreto–SP.RevInsAdolfoLutz.1999;58:41–6.

30.TavechioAT,GhilardiACR,PeresiJTM,etal.Salmonella serotypesisolatedfromnonhumansourcesinSãoPaulo, Brazil,from1996though2000.JFoodProt.2002;65:1041–4.

31.BryanFL,DoyleMP.Healthrisksandconsequencesof SalmonellaandCampylobacterjejuniinrawpoultry.JFoodProt. 1995;58:326–44.

32.ForsytheSJ.Microbiologiadaseguranc¸aalimentar.Porto Alegre:Artmed;2002,424p.

33.SharmaKB,BheemBhatM,PasrichaA,VazeS.Multiple antibioticresistanceamongsalmonellaeinIndia.J AntimicrobChemother.1979;5:15–21.

34.CentersforDiseaseControlandPrevention–CDC. MultiresistantSalmonellaandotherinfectionsinadopted infantsfromIndia.MorbMortalWklyRep.1982;31:285–7. Availableat:http://www.cdc.gov/mmwr/preview/mmwrhtml/ 00001106.htm[accessed18.03.14].

35.HopkinsKL,DaviesRH,ThrefallEJ.Mechanismsofquinolone resistanceinEscherichiacoliandSalmonella:recent

developments.IntJAntimicrobAgents.2005;25:358–73.

36.GiraudE,BaucheronS,CloeckaertA.Resistanceto fluoroquinolonesinSalmonella:emergingmechanismsand resistancepreventionstrategies.MicrobesInfect.

2006;8:1937–44.

37.FerrariR,GalianaA,CremadesR,etal.Plasmid-mediated quinoloneresistancebygenesqnrA1andqnrB19inSalmonella strainsisolatedinBrazil.JInfectDevCtries.2011;5:

496–8.

38.CamposJ,PichelM,VazTMI,etal.BuildingPulseNetLatin AmericaandCaribbeanSalmonellaregionaldatabase:first conclusionsofgeneticsubtypesofS.Typhi,S.Typhimurium andS.Enteritidiscirculatinginsixcountriesoftheregion. FoodResInt.2012;45:1030–6.